102 I PART 1 I CLIMATE IN VIET NAM: PAST, PRESENT AND FUTURE
reconstitute past climatic trends — we would like to return to the importance of organising their complementarity. It is only at the price of critical work on the sources, which really puts the quality of the climatic data to the test, that we will be able to claim to be able to make use of these data to draw up climatic series that will be usable by climatologists. For this to be possible, the historical data must be recorded
4. Contemporary climate history 4.1 French meteorological service during the colonial period Colonial meteorological services are an important source for writing the contemporary climate history of Viet Nam. They provide the first modern statistical series that are readily available to sketch a history of the climate in the 19th and first half of the 20th centuries. The colonial administration progressively set up a meteorological and climatological service in Indochina, in charge of systematizing the recording of meteorological and climatic data in Indochina. Over the years, it developed a relatively dense network of meteorological stations, as shown on the map of these stations published in 1931 at the time of the Paris Colonial Exhibition [ Figure 2.8 ]. Actually, meteorological and climatological services took some time to be established during the French colonisation. The process started in Cochinchina, where the Agricultural chamber and the Agricultural and Industrial Committee published some meteorological information in
in accordance with criteria that are recognised as reliable climate data by historians, meteorologists and climatologists alike . Among these criteria, the analysis of possible biases at the time of recording the data is a crucial point, which falls within the historian’s domain. This is an issue that we will return to in connection with the use of climate data from the colonial period, which we will now examine.
their Bulletin between 1865 and 1883, but no real meteorological service existed during the XIXth century. The first weather stations were established in 1897 [ Lespagnol, 1902 ], and it was only in 1900, under the impetus of Governor General Paul Doumer, that the first unified Meteorological Service was set up. Around 10 principal stations and 20 secondary ones composed the network for the whole of Indochina (Annales de Géographie, 1900 ] 2. From this date onwards and throughout the period of colonisation, the Bulletin Économique de l’Indochine published the monthly observations of the entire network. This network of stations was completed in 1902 by the creation of the Central Meteorological Observatory in PhủLiễn (9 km from Haiphong), in the typhoon ac2. Saigon, Cap Saint-Jacques, Poulo-Condore, Ong-Yeni, Tayninh and Soc-trang (for Cochinchina); Nha-trang, Langsa, Tourane, Quin-hone, Hué, Dong-Hoi, Vinh and Than-hoa (for Annam); Hanoi, Haiphong, Quang-Yen, Hon-gay, Mon-cay, Lang-son, Cao-bang, Lao-kay, Ha-giang, Bac-кап and Van-bu (for Tonkin); Vientiane, Luang-Prabang, Savannakhek, Khong and Attopeu (in Laos); Pnom-penh, Kampot and Pursat (in Cambodia). (La météotrologie dans L’Indo-Chine Française, Annales de Géographie, IX, 1900, p. 178. ] 3. Voir Annales de Géographie (Bibliographie de 1899 n° 571 et de 1900, n° 506) ; dans le Bulletin Économique de l’Indochine, IV, 1901, Le Lay a publié “Climatologie comparée île Manille et des Stations de Backan et Hagiang dans le bassin de la Rivière Claire (Haut Tonkin), du 1er novembre 1899 au 31 octobre 1900”, pp. 139-144 ; “Résumé des observations des stations météorologiques primaires et secondaires de l’Indo-Chine pendant l’année 1900, pp. 243-259, etc.; de Beljonne, une intéressante étude : “Observations sur les moussons en Indo-Chine ”, pp. 797-801, cartes.
